Overview

• Phones on 4G or 5G will emit a loud sound and vibrate for about 10 seconds at 3pm on Sunday, 7 September, delivering a test message that requires no action.
• Devices that are switched off, Wi‑Fi only, or on 2G/3G will not receive the alert; messages are sent based on a phone’s current location and do not require location services to be turned on.
• The test text will appear in English and Welsh and directs people to gov.uk/alerts, with government materials also pointing to gov.uk/prepare for guidance.
• Ahead of the drill, the government is running a public information campaign with a national British Sign Language video and advice tailored for vulnerable groups such as domestic abuse survivors.
• Since the first national test in April 2023, alerts have been used locally five times, including during Storm Eowyn and Storm Darragh, flooding in Cumbria and Leicestershire, and a 500kg WWII bomb in Plymouth; the 2023 test reached about 93% of phones and some MPs want additional non‑mobile channels such as printed guidance.